Dental patients chair with automatic actuation

ABSTRACT

A dental patients&#39;&#39; chair has an upper part consisting of an adjustable seat and an adjustable back, a carrier supporting the upper part, a carrying arm used for adjusting the height of the upper part which is swingably connected with the carrier and is connected with a base, devices for adjusting the seat and the back and an electrical steering device for the adjusting devices for automatically providing preselected and adjustable positions of the seat and back. The invention is particularly characterized in that constructional parts of the steering device are located upon a preferably common supporting part in or at the carrier supporting the upper part and are covered by a removable covering.

United States Patent Heubeck Feb. 18, 1975 DENTAL PATIENTS CHAIR WITH 3,188,136 6/1965 Redfleld et al. 297/71 AUTOMATIC ACTUATION 3,330,595 7/1967 Sv'alrd 297/71 3,514,153 5/1970 Maurer et all 297/71 Inventor: Erleh Heubeek, Behshelm, Germany 3,578,379 5/1971 Taylor 297/71 [73] Assigneez Siemens Akfiengeseuschaft, 3,804,460 4/1974 Leffler 297/71 Erlangen, Germany Primary Examiner-James T. McCall [22] Flled: 1973 Attorney, Agent, or FirmRichards & Geier 211 Appl. 190.; 407,258

- [57] ABSTRACT [30] Foreign Application Priority Data A dental patients chair has an upper part consisting of on. 21, 1972 Germany 2251737 adjustable Seat and an adjustable back a Carrier supporting the upper part, a carrying arm used for ad 521 [1.5. Ci 297/316, 297/71, 297/330, J e the height of the pp P whieh is Swingehly 297/345, 297/354 connected with the carrier and is connected with a 51] Int. Cl A61g 15/00 base, deviees for adjusting the Seat and the haek and [5 Field f Search 297 7 3 5 347, an electrical steering device for the adjusting devices 297 1 343 3 34 2 4 05 for automatically providing preselected and adjustable 32/22; 338/121 5 200 positions of the seat and back. The invention is particularly characterized in that constructional parts of the 5 References Cited steering device are located upon a preferably common UNITED STATES PATENTS supporting part in or at the camer supporting the 2 714 922 8/1955 McKibban 297/330 x upper part and are covered by a removable covermg. 2,982,335 5/1961 Garvey 8 Claims, 9 Drawing Figures PATENTED FEB I 1915 SHEET 2 BF 4 DENTAL PATIENTS CHAIR WITH AUTOMATIC ACTUATION This invention relates to a dental patients chair having an upper part consisting of an adjustable seat and an adjustable back, a carrier supporting the upper part, a carrying arm used for adjusting the height of the upper part and swingably connected on one side with the carrier and on the other side with a base, devices for adjusting the seat and the back and an electrical steering device for the adjusting devices for automatically providing preselected and adjustable positions of the chair and back.

An electrical steering device of this type is described in the two German Pat. applications P1223262 and P1961477. The last-mentioned specification describes the provision of rated value and actual value indicators to provide a desired chair position and to indicate a momentary chair position. The rated value indicators are arranged in a box-like casing which, for example, can be attached on a wall of doctors room which also contains the patients chair. The actual value indicators are mounted separately from the rated value indicators upon a suitable location in the chair. This arrangement of the steering device has certain drawbacks. The steering cable extending from the switch casing for the rated value indicators to the patients chair is a disturbance particularly when such a steering device has been subsequently provided and must be moved for cleaning. In general a subsequent application of such a steering device to a chair is a problem and requires a comparatively large mounting expenditure. Furthermore, errors which may appear in the steering device can be removed only with a great loss of time since the service man in order to search for the source of error must examine parts in the chair as well as parts outside the chair, including the operating cable.

An object of the present invention is the provision of a dental patients chair of the described type which will not have the above-mentioned drawbacks. Particularly,

' the chair of the present invention should be so constructed that the steering device can be easily installed, that subsequent arrangements can be carried out comparatively simply and quickly and that adjustments and servicing of the steering device can be carried out without a great loss of time.

In the accomplishment of the objectives of the present invention it was found desirable to provide a dental patients chair of the described type wherein constructional parts of the steering device are located upon a preferably common supporting part in or at the carrier of the upper part and are covered by a removable cov-,

ering.

This central arrangement of the constructional parts which does not affect their function, provides a great simplification in the mounting, particularly when the chair is subsequently provided with such a steering device, as well as a noticeable simplification of servicing.

To avoid damages or improper shifting of the setting parts of this automatic steering, it is advantageous to cover the carrying part or the closure with the setting members located therein by a hood which is to be opened in operation, namely, without the use of a tool. It is advantageous when the supporting part and the covering are arranged upon the front side of the boxlike seat carrier adjacent the back. This location is particularly easily accessable, since due to the swinging of the back no other tools or the like can be arranged within a close range, so that when the back is straightened, the operator can easily reach the seat carrier and thus the operating location.

Other advantageous constructions and embodiments of the present invention are described and claimed hereinafter. The accompanying drawings show by way of example only, a preferred embodiment of the inventive idea.

In the drawings:

FIG. 1 is a perspective view of a dental patients chair of the present invention.

FIG. 2 is a perspective view of the seat carrier looking from the back of the chair.

FIG. 3 is a diagrammatic perspective view showing details of the adjusting device for the seat and the back. FIGS. 4 and 5 show two different positions of the parallelogram carrier in longitudinal section along line IIII of FIG. 2 in greatly simplified form.

FIGS. 6 and 7 show two different positions of the seat in longitudinal section along the line IIII of FIG. 2

. also in greatly simplified form.

- 5 can be tipped relatively to the carrier 3 about an axle extending transversely tothe longitudinal axis of the chair and not shown in the drawing. Switches 7 and 8 located upon the back of the chair operate the three adjusting movements, namely, the inclination of the back, the tipping and the height movement of the seat. The switches 7 and 8 are so arranged upon the upper part of the back 4 that they can be operated from the rear as well as from the upper side of the back. Three keys 9 can be used to select three preset chair positions. Details will be described hereinafter.

The back 4 is connected by an axle bearing 10 with one end of angularly fixed rods 11 constituting arm supports. Their other end is connected by an axle bearing 12 to the seat carrier 3. Due to this arrangement, as described in detail hereinafter, it is possible to provide a combined movement of the back and seat with a single drive.

The base 1 is provided in its front part on both sides with two vertical side walls 13 upon which the parallelogram carrying arm 2 is swingably mounted by axle bearings l8, 19. The arm 2 carries covers 16, 17 which are used to cover connections shown in the following figures. The two other axle bearings of the arm 2 are indicated as 20 and 21. The arm 2 can be moved from the illustrated position into a deep position in which it extends substantially horizontally. A step plate 14 is located in the back of the base 1. When the plate 14 is stepped on, the adjusting drive for the adjustment of the parallelogram arm 2 is switched off.

FIG. 2 shows the upper chair part carrier 3 from the back of the chair. Axle bearings 22 and 23 carry a shifting device 39 for the seat and the back. In the rear part of the box-shaped seat carrier 3 close to the lower edge of the back 4 there is a baffle space 24 in which a covering part 25 is arranged which is swingable about a horizontal axle 26. The covering part can be covered by a cap 27 which is also swingabl-e. Two vertical rows of setting members 28, 29 as well as a program selecting switch 30 are located upon the front side of the covering part 25. The setting members 28, 29 are connected with potentiometers located upon a conducting plate 31 constituting a support for the structural elements of the steering device. The steering device can be used to provide three chair positions preselected by the setting members 28, 29 which can be moved by actuating one of the keys 9 located upon the backof the chair under the switches 7 and 8. When a key 9 is actuated the chair is moved automatically into a position previously determined by the setting members 28 and 29. The three setting members 28 of the right hand row can provide three different height positions of the seat. Thus each of the three setting members 28 provides a different height of the chair. Similarly the three setting members 29 of the left hand row can preset three programmed inclining or tipping positions of the seat and the back. The program selecting switch 30 is used to set one of the three programs (upper, middle or bottom transverse row). As rated value indicators are provided regulatable resistances ofthe type described in German Pat. application P1923262, coupled with different other electronic structural elements. This switch structure as well as other particulars of the electronic part of the actuating device are described in that application. FIG. 2 shows fuses 32 which can'also conveniently reached after swinging the cover 27.

Two actual value indicators 33, 34 are provided upon the rear side of the carrying part 31. One of them cooperates with the part 36 of the parallelogram carrying arm 2 and thus indicates the prevailing height position of the upper part of the chair. The other one is connected by another rod part 46 with the seat 5 and thus indicates the actual tipping location of the seat or the back.

The supporting plate 31 can be also made of two parts, whereby one part contains the rate value indicators with the corresponding setting members 28 and 29 and the second part the actual value indicators 33, 34. The advantage of the two constructions is that all structural parts necessary for the operation of the program (as indicated in German Pat. application P1923262) are conveniently located in the chamber 24. The entire unit can be very easily removed from the chair and separated from the chair upper part carrier for servicing and upkeep. for that purpose it is merely necessary to pull the carrying plate 31 out ofa plug socket. The plug socket is a part of a voltage supply 35 which contains a transformer with contacts and switch relays etc. necessary for supplying the actuating device and which are mounted upon the covering 25.

FIG. 3 shows in perspective details of the shifting device for the seat and back, as well as details of the parallelogram carrying arm '2. The parallelogram carrying arm 2 is constituted by a box-like frame 36 of U-shaped cross-section and rods 37, 38 located on both sides. In FIG. 1 they are covered by the coverings 16, 17. The seat 5 is movable longitudinally by a shifting device 39 not shown in detail. The device 39 can be swung by axles 22, 23 extending transversely to the longitudinal axis of the chair. The seat 5 also has run up rails 40. Rollers 41 support the rails in such manner that when the seat 5 is moved longitudinally it is raised over the rollers. A spindle 42 driven by an electromotor is provided as the adjusting device. The rigid support indicated by the numeral 11 inFlG. 1 serves as a guide and provides a front shifting of the seat when the base is inclined. Each arm support consists of two angularly fixed rods 11, as shown. An axle bearing 10 connects the arm support to the back 4, and another axle bearing 12 connects the arm support to the seat carrier 3. When the device shown in FIG. 3 pushes the seat 5 forward, a relative movement takes place between the seat 5 and the seat carrier 3, which, due to the provision of the axle bearing 12, causes automatically an inclination of the back. In reverse, when the back is inclined over the arm supports, the seat is automatically pushed forward.

FIGS. 4 and 5 show the arrangement and location of the actual value transmitter in two different height positions of the seat. FIG. 4 shows the seat in its highest position and FIG. 5 shows it in its lowermost position. Parts which are not absolutely necessary for the explanation of the device have been left out for better clarity.

A rotary potentiometer 33 constituting a part of the actual value transmitter is mounted upon the plate 31 which is fixed upon the covering part 25. Its rotary axis is connected with a key finger 44 the front end of which lies by means of a roller 45 upon an upper edge of a side piece of the U-shaped frame 36. The actual value transmitter includes the rotary potentiometer 33, the transmission members 50 and 51, the key finger 44 and a roller 45. As shown in FIG. 4, the roller 45 is a guid- 'ing roll engaging an end portion of the parallelogram with rated values of the rated value indicators by electronic parts arranged in compressed switching upon the conducting plate 31in a switch arrangement corresponding to that indicated in the above-mentioned patent application. When the two values are the same there is no signalat the outlet of the adjusting device (adjusting drive 42). When the rated values and actual values are different the adjusting device is moved in one or the other direction. For the sake of clarity a greatly simplified illustration has been selected for the drawings and the seat mounting has not been shown in detail in the two figures.

FIGS. 6 and 7 show in two tipping positions of the seat the arrangement and connection of the actual value indicator 34 provided for indicating the position of the back and the seat relatively to the carrier 3. As has been indicated already in FIG. 3 the actual value indicator 34 is connected with the seat 5 by rods 46. The seat 5 is shown in FIG. 6 in a position tipped in relation to the horizontal. If the seat is moved back to the normal position (FIG. 7) the actual value indicator 34 will be shifted by the longitudinal movement of the seat through the rods 46 and this produces a change in the resistance value of thecorresponding potentiometer. This resistance is also connected by electrical connections described in the above-mentioned patent application with the corresponding rated value givers and produces depending upon position a shifting of the chair in one or the other direction.

FIG. 8 shows enlarged the plate 31 upon which are located the actual value indicator 33 for indicating the height location of the chair and the actual value indicator 34 for indicating the tipping location of back and seat. The drawing shows well the connections of the actual value indicator 34 with the rod 46. Two adjusting screws 47 are used for adjusting the two actual value indicators 33 and 34. They are accessible from the operating side of the cover 25 (H0. 2). A plug strip 48 can be inserted into a correspondingly shaped part of the device 35.

The arrangement and construction of the illustrated and described type has the advantage that the chair may be provided with automatic actuation with only a few hand grips. For that purpose it is merely necessary to couple the plate 31 upon which are arranged all parts for automatic actuation, including the rated value and actual value indicators, with the supplying device 35 and to adjust the actual value indicators by the screws 47. The supporting surface of the key finger 44, i.e., of the roller 45 of the corresponding actual value indicator 33 can be varied by the adjusting screws 47 and thus the actual value indicator can be adapted to the location of the chair. Numerals 50 and 51 indicate transmission members for transmitting the movement of the key finger to the rotary potentiometer.

I claim:

1. A dental patients chair, comprising a chair upper part having an adjustable seat and an adjustable back, a carrier supporting said upper part, a base, a parallelogram carrying arm connected with said carrier and said base for adjusting the height of said upper part, devices for shifting said seat and said back, an electrical actuating device for said shifting devices, said actuating device comprising a rotary potentiometer constituting an actual value transmitter and having an axle and a key finger connected with said axle, said finger having a free end engaging the part of said parallelogram arm connected with said carrier and changing its position when the height position of the seat is changed for the purpose of detecting the change of the seat position relatively to the base, a value transmitter, a setting member connected with the last-mentioned transmitter to preset a selected position for the seat and a supporting part arranged on said carrier and carrying the lastmentioned transmitter and said setting member.

2. A dental patients chair according to claim 1, com prising a rotary potentiometer constituting an actual value transmitter having an axle and a key finger connected with said axle, and a rod connected with said back, said finger having a free end engaging said rod for detecting the change of seat and back positions relatively to said carrier, a value transmitter and a setting member connected with the last-mentioned transmitter to preset a selected position for the back, the lastmentioned transmitter and said setting member being carried by said supporting part.

3. A dental patients chair according to claim 1, comprising means for adjusting said finger, and wherein said supporting part carries the first-mentioned transmitter and said means for adjusting said finger.

4. A dental patients chair according to claim 3, wherein said electrical actuating device has current supplying means, said supporting part having a plug strip connecting it with said current supplying means.

5. A dental patients chair according to claim 4, comprising a covering, said supporting part and at least a part of said current-supplying means being carried by said covering.

6. A dental patients chair according toclaim 5, wherein said covering is swingably connected to said carrier.

7. A dental patients chair according to claim 6, having a cap over said covering.

8. A dental patients chair according to claim 7, wherein said carrier is box-shaped and has a front side adjacent the back, said supporting part and said covering being located at said side. 

1. A dental patients'' chair, comprising a chair upper part having an adjustable seat and an adjustable back, a carrier supporting said upper part, a base, a parallelogram carrying arm connected with said carrier and said base for adjusting the height of said upper part, devices for shifting said seat and said back, an electrical actuating device for said shifting devices, said actuating device comprising a rotary potentiometer constituting an actual value transmitter and having an axle and a key finger connected with said axle, said finger having a free end engaging the part of said parallelogram arm connected with said carrier and changing its position when the height position of the seat is changed for the purpose of detecting the change of the seat position relatively to the base, a value transmitter, a setting member connected with the last-mentioned transmitter to preset a selected position for the seat and a supporting part arranged on said carrier and carrying the last-mentioned transmitter and said setting member.
 2. A dental patients'' chair according to claim 1, comprising a rotary potentiometer constituting an actual value transmitter having an axle and a key finger connected with said axle, and a rod connected with said back, said finger having a free end engaging said rod for detecting the change of seat and back positions relatively to said carrier, a value transmitter and a setting member connected with the last-mentioned transmitter to preset a selected position for the back, the last-mentioned transmitter and said setting member being carried by said supporting part.
 3. A dental patients'' chair according to claim 1, comprising means for adjusting said finger, and wherein said supporting part carries the first-mentioned transmitter and said means for adjusting said finger.
 4. A dental patients'' chair according to claim 3, wherein said electrical actuating device has current supplying means, said supporting part having a plug strip connecting it with said current supplying means.
 5. A dental patients'' chair according to claim 4, comprising a covering, said supporting part and at least a part of said current-supplying means being carried by said covering.
 6. A dental patients'' chair according to claim 5, wherein said covering is swingably connected to said carrier.
 7. A dental patients'' chair according to claim 6, having a cap over said covering.
 8. A dental patients'' chair according to claim 7, wherein said carrier is box-shaped and has a front side adjacent the back, said supporting part and said covering being located at said side. 